Swimming Activity Research Articles

Enhancing Botrytis disease management in tomato plants: insights from a Pseudomonas putida strain with biocontrol activity.

This study explores the biocontrol potential of Pseudomonas putida Z13 against Botrytis cinerea in tomato plants, addressing challenges posed by the pathogen's fungicide resistance. The aims of the study were to investigate the in vitro and in silico biocontrol traits of Z13, identify its plant colonizing efficacy, evaluate the efficacy of different application strategies against B. cinerea in planta, and assess the capacity of Z13 to trigger induced systemic resistance (ISR) in plants. The in vitro experiments revealed that Z13 inhibits the growth of B. cinerea, produces siderophores, and exhibits swimming and swarming activity. Additionally, the Z13 genome harbors genes that encode compounds triggering ISR, such as pyoverdine and pyrroloquinoline quinone. Τhe in planta experiments demonstrated Z13's efficacy in effectively colonizing the rhizosphere and leaves of tomato plants. Therefore, three application strategies of Z13 were evaluated against B. cinerea: root drenching, foliar spray, and the combination of root drenching and foliar spray. It was demonstrated that the most effective treatment of Z13 against B. cinerea was the combination of root drenching and foliar spray. Transcriptomic analysis showed that Z13 upregulates the expression of the plant defense-related genes PR1 and PIN2 upon B. cinerea inoculation. The results of the study demonstrated that Z13 possesses significant biocontrol traits, such as the production of siderophores, resulting in significant plant protection against B. cinerea when applied as a single treatment to the rhizosphere or in combination with leaf spraying. Additionally, it was shown that Z13 root colonization primes plant defenses against the pathogen.

Waterborne exposure to the antineoplastic 5-fluorouracil alters lipid composition in larval zebrafish (Danio rerio).

Antineoplastic medications are present in aquatic environments, measured at relatively high concentrations in hospital sewage effluent. It is thus important to characterize risk associated with waterborne exposures to anticancer drugs. The drug 5-fluorouracil (5-FU) is used to treat several types of cancers, acting to inhibit cell division and cellular metabolism. The objectives of this study were to determine the effects of 5-FU on developmental endpoints and lipid composition in zebrafish. 5-FU did not negatively affect development nor survival in developing zebrafish at concentrations up to 1000 μg/L. However, 5-FU increased neutral lipid content in zebrafish larvae, indicating potential for lipid dysregulation. To further discern effects on lipids, lipidomics was conducted and a total of 164 lipids belonging to 14 lipid classes were identified. Significant changes (false discovery rate < 0.05) in abundance were detected for 19 lipids including some ceramides, ether-linked phosphatidylethanolamines, and sphingomyelins among others. We also measured the expression levels of 14 lipid-related enzymes and transporters (e.g., acox3, dgat1, fads2, fasn, elovl2) using real-time PCR; however, mRNA abundance levels were not affected, suggesting transcriptional changes may not be a primary mechanism underlying lipid dysregulation. Locomotor activity was also measured in zebrafish, as lipids are needed for swimming activity in larvae. Exposure to 5-FU did not affect locomotor activity up to 1000 μg/L. We conclude that lipids accumulate in larval zebrafish with exposure to 5-FU, which can subsequently affect lipid composition. These data reveal potential lipid signatures of 5-FU exposure and contribute to risk assessments for antineoplastic exposure in aquatic environments.

Embryotoxicity Induced by Triclopyr in Zebrafish (Danio rerio) Early Life Stage

Triclopyr, an auxin-like herbicide that is widely employed for managing weeds in food crops and pastures, has been identified in various environmental settings, particularly aquatic ecosystems. Limited understanding of the environmental fate of this herbicide, its potential repercussions for both the environment and human health, and its insufficient monitoring in diverse environmental compartments has caused it to be recognized as an emerging contaminant of concern. In this study, we have investigated how triclopyr affects zebrafish, considering a new alternative methodology. We focused on the endpoints of developmental toxicity, neurotoxicity, and behavior of zebrafish embryos and larvae. We determined that triclopyr has a 96 h median lethal concentration of 87.46 mg/L (341.01 µM). When we exposed zebrafish embryos to sublethal triclopyr concentrations (0.5, 1, 5, 10, and 50 μM) for up to 144 h, we found that 50 µM triclopyr delayed zebrafish egg hatchability. Yolk sac malabsorption was significant at 0.5, 1, 5, and 10 µM triclopyr. In zebrafish larvae, uninflated swim bladder was significant only at 50 µM triclopyr. Furthermore, zebrafish larvae had altered swimming activity after exposure to 10 µM triclopyr for 144 h. In summary, these comprehensive results indicate that even low triclopyr concentrations can elicit adverse effects during early zebrafish development.

Differential impact of diesel exhaust particles on glutamatergic and dopaminergic neurons in Caenorhabditis elegans: A neurodegenerative perspective

The growing body of evidence links exposure to particulate matter pollutants with an increased risk of neurodegenerative diseases. In the present study, we investigated whether diesel exhaust particles can induce neurobehavioral alterations associated with neurodegenerative effects on glutamatergic and dopaminergic neurons in Caenorhabditis elegans (C. elegans). Exposure to DEP at concentrations of 0.167 µg/cm2 and 1.67 µg/cm2 resulted in significant developmental delays and altered locomotion behaviour. These effects were accompanied by discernible alterations in the expressions of antioxidant genes sod-3 and gst-4 observed in transgenic strains. Behaviour analysis demonstrated a significant reduction in average speed (p < 0.001), altered paths, and decreased swimming activities (p < 0.01), particularly at mid and high doses. Subsequent assessment of neurodegeneration markers in glutamatergic (DA1240) and dopaminergic (BZ555) transgenic worms revealed notable glutamatergic neuron degeneration at 0.167 μg/cm2 (∼30 % moderate, ∼20 % advanced) and 1.67 μg/cm2 (∼28 % moderate, ∼24 % advanced, p < 0.0001), while dopaminergic neurons exhibited structural deformities (∼16 %) without significant degeneration in terms of blebs and breaks. Furthermore, in silico docking simulations suggest the presence of an antagonistic competitive inhibition induced by DEP in the evaluated neuro-targets, stronger for the glutamatergic transporter than for the dopaminergic receptor from the comparative binding affinity point of view. The results underscore DEP's distinctive neurodegenerative effects and suggest a link between locomotion defects and glutamatergic neurodegeneration in C. elegans, providing insights into environmental health risks assessment.

URINARY SCHISTOSOMIASIS AMONG SCHOOL-AGE CHILDREN IN SELECTED RURAL COMMUNITIES IN HADHRAMOUT GOVERNORATE, YEMEN

Background: Urinary schistosomiasis is a potentially life-threatening public health issue in some areas of Yemen, particularly in Hadhramout rural communities. It is considered as one of the most common neglected tropical parasitic diseases. This study aimed to investigate the prevalence of urinary schistosomiasis and associated risk factors among school-age males and females in selected rural communities of Hadhramout, Yemen. Methods: A total of 450 students participated in this cross-sectional study. Urine samples were collected, then examined for haematuria and Schistosoma haematobium (S. haematobium) eggs using urine dipsticks and filtration technique respectively. To assess knowledge and practices regarding the transmission of urinary schistosomiasis, a pre-tested questionnaire was employed. Results: An overall (66)14.7% of participants tested positive for S. haematobium, and of those, 54 (12.0%) developed haematuria with a statistically significant difference (p=0.001). A total of 35(53.0% eggs/10 ml urine) had heavy intensity of infection, with a significant difference (p=0.001) between the different communities visited: high in Al-Dhulaya'a (18.2 eggs/10 ml urine) and low in Yabaith (6.1 eggs/10 ml urine). S. haematobium infection showed significantly higher (p=0.002) in males (13.8%) than females (0.9%), and increased with age of participants. Multivariate logistic analysis of risk factors were significantly associated with the prevalence of urinary schistosomiasis such as swimming activities (p=0.016), washing clothes (p=0.14), time spent in infested areas more than 15 minutes (p=0.012), habits of defecation/urination in open water sources (p=0.44), self-reported symptoms suggestive of the disease (p=0.03), participants with a history of illness (p=0.014), lack of awareness of schistosomiasis (p=0.050), and no prior treatment with praziquantel (p=0.001). Conclusions: Urinary schistosomiasis remains highly prevalent among schoolchildren in rural communities in Hadhramaut. The study highlights the urgent need to implement preventive measures, safe drinking water supply, proper sanitation, and vector control programs in order to reduce transmission and morbidity caused by schistosomiasis.                       Peer Review History: Received 3 December 2023;   Revised 28 January 2024; Accepted 27 February; Available online 15 March 2024 Academic Editor: Dr. Marwa A. A. Fayed, University of Sadat City, Egypt, maafayed@gmail.com Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Dr. Owanaro Peter, Nigeria,  Department of Clinical Pharmacy and Pharmacy Practice, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria. owonaropeter@gmail.com Dr. George Zhu, Tehran University of Medical Sciences, Tehran, Iran, sansan4240732@163.com

Toxic effects and comparison of common amino antioxidants (AAOs) in the environment on zebrafish: A comprehensive analysis based on cells, embryos, and adult fish

The ubiquity of amino antioxidants (AAOs) in the environment has attracted increasing attention, given their potential toxicity. This investigation represents a pioneering effort, systematically scrutinizing the toxicological effects of four distinct AAOs across the developmental spectrum of zebrafish, encompassing embryonic, larvae, and adult stages. The results indicate that four types of AAO exhibit varying degrees of cell proliferation toxicity. Although environmentally relevant concentrations of AAOs exhibit a comparatively circumscribed impact on zebrafish embryo development, heightened concentrations (300 μg/L) of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) and N-isopropyl-N′-phenyl-p-phenylenediamine (IPPD) distinctly evoke developmental toxicity. Behavioral analysis results indicate that at concentrations of 20 and 300 μg/L, the majority of AAOs significantly reduced the swimming speed and activity of larvae. Moreover, each AAO triggers the generation of reactive oxygen species (ROS) in larvae, instigating diverse levels of oxidative stress. The study delineates parallel toxicological patterns in zebrafish exposed to 300 μg/L of 6PPD and IPPD, thereby establishing a comparable toxicity profile. The comprehensive toxicity effects among the four AAOs is as follows: IPPD >6PPD > N-Phenyl-1-naphthylamine (PANA) > diphenylamine (DPA). These findings not only enrich our comprehension of the potential hazards associated with AAOs but also provide data support for structure-based toxicity prediction models.

Phenotype‐dependent downstream dispersal under ordinary flow conditions in juvenile white‐spotted char

AbstractAnimal dispersal is often phenotype‐dependent and can exert evolutionary pressures on populations in which it occurs. The evolutionary pressure arising from phenotype‐dependent dispersal is called spatial sorting. We examined the evolutionary pressure arising from spatial sorting (sorting pressure) caused by downstream dispersal in juvenile white‐spotted char Salvelinus leucomaenis under ordinary flow conditions. We conducted outdoor experiments using an artificial channel with 10 steps to investigate the relationship between phenotypic characteristics and the occurrence or distance of downstream dispersal during five daytime hours. Six experiments were conducted using young‐of‐the‐year juveniles collected early in the morning of each experimental day. We focused on two phenotypes, fork length (body size) and station‐holding (SH) behavior, where juveniles remain sedentary on the substrate. Juveniles were assigned to the “SH group” if they exhibited SH behavior for more than 10 s during a 540‐s observation period, and to the “swimming group” if they exhibited SH behavior for less than 10 s. Juveniles in the swimming group had a higher occurrence of downstream dispersal than in the SH group. In addition, large juveniles in the SH group and small juveniles in the swimming group tended to show long dispersal distances. These results suggest an effective sorting pressure against juveniles with active swimming behavior. This sorting pressure may accumulate in isolated char populations located above a tall migration barrier and contribute to the creation and maintenance of the reported interpopulation variation in SH behavior.

Alert System to Prevent Drowning using IoT- A Survey

Swimming is a popular sport as it is a pleasant recreational hobby. Aside from its physical benefits, it also relieves stress and gives a sense of peace. So, it is highly preferred by children’s, adults, and sometimes even elderly people. Many countries have made swimming and other life skills compulsory activities in school to avoid fatalities in the event of disaster. While swimming has many advantages, safety precautions are paramount to avoid unintentional deaths. While various drowning prevention systems and technologies have been developed, many of them lack accuracy in detecting drowning incidents and fail to provide an effective rescue mechanism for swimmers in distress. To develop a smart anti-drowning and alert system, this study presents a comprehensive survey of existing drowning systems and suggests a proposed model in response to the identified gaps and challenges in current systems. The suggested framework includes Arduino microcontrollers, voice recognition technology, ultrasonic sensors, and alert generators. The proposed approach not only addresses the constraints of existing systems, but it also provides a cost-effective and scalable solution that can be used in a variety of water environments, including pools and natural bodies of water. The suggested system has the potential to reduce reaction times in emergency circumstances, adding to the overall enhancement of water safety. Future research could focus on practical implementation, testing, and improvement of the proposed model to improve its usefulness in reducing drowning accidents.

생존수영 참여 초등학생의 수상안전사고, 수중불안, 지속의도의 관계

This study purpose to investigate the relationships water safety incidents, aquatic anxiety, and intention to continuous of elementary students participating in survival swimming. The study participants 358 elementary grades 3 to 6 experience participating in survival swimming. Statistical analysis using the SPSS, AMOS. The analysis included reliability, correlation, exploratory factor, confirmatory factor analysis, and structural equation modeling. First, aquatic safety incidents were found to be partially influenced by aquatic anxiety. Second, aquatic safety incidents were found to partially affect the intention to continue. Third, aquatic anxiety was found to partially influence the intention to continue. Conclusion, It can be understood that elementary school students participating in survival swimming should receive pre-education on water safety incidents related to swimming pools/water parks, boats, water safety education, in order to reduce underwater anxiety and sustain survival swimming. Comparing the intention to continuous in survival swimming based on pre-swimming experience, it would greatly contribute to the activation of survival swimming.

Unintentional injury deaths associated with sport and recreation in Québec, Canada, 2006–2019

ObjectivesThis study examined trends in the frequencies and rates of deaths associated with unintentional injuries in sport and recreation in Québec, Canada, for the period January 2006–December 2019.MethodsIn this descriptive...

The effect of swimming activity and feed restriction of rainbow trout (Oncorhynchus mykiss) on water quality and fish-plant growth performance in aquaponics.

In this study, we investigated the effects of swimming activity and feed restriction on juvenile rainbow trout (Oncorhynchus mykiss) in decoupled aquaponic systems. Our focus was on assessing their impact on water quality parameters within the aquaponic setup and evaluating the growth performance of the fish, including final weight (FW), condition factor (K), coefficient of variation (c.v.) in weight, specific growth rate (SGR), total feed intake (g/fish), feed conversion rate (FCR), hepatosomatic index (HSI), and viscerosomatic index (VSI), as well as the growth of lettuce (Lactuca sativa L. var. elmaria). The study involved 108 juvenile rainbow trout with an average initial weight of 26.54 ± 0.36 g and 60 ten-day-old lettuce seedlings, over a period of 42 days. We designed four treatment groups, each with three fish tanks: static ad libitum (SA), where fish were in static water conditions and fed to satiation; static restriction (SR), with fish in static water and a 25% feed restriction; current ad libitum (CA), where fish experienced forced swimming at 1 BL s-1 ; and current restriction (CR), with swimming exercise at 1 BL s-1 and a 25% feed restriction. Using a flow rate of 1 BL s-1 in the tanks for rainbow trout yielded several benefits. Notably, the fish in the CA group exhibited increased feed intake (60 ± 1.78 g fish-1 ) and enhanced fish growth with an FW of 91.72 ± 0.91 g, compared to the SA group (55.88 ± 0.88 g fish-1 for feed intake and 89.26 ± 0.81 g for FW). In contrast, the CR group showed a reduced feed intake (39.02 ± 2.78 g fish-1 ) and a lower FW (67.85 ± 1.49 g) compared to the CA group. In addition, the CA group demonstrated positive contributions to fish development with a reduced HSI (1.26 ± 0.02) in comparison to the SA group (1.56 ± 0.14). Inadequate nutrient provisioning in the SR and CR groups negatively impacted fish growth and system efficiency. Our findings suggest that optimizing water flow and feed benefits fish and plants and enhances system sustainability.

The effects of plastic additives on swimming activity and startle response in marine amphipod Echinogammarus marinus

Plastic additives are widely used in plastic production and are found in the environment owing to their widespread applications. Among these additives, N-butyl benzenesulfonamide (NBBS) and triphenyl phosphate (TPHP) are under international watchlist for evaluation, with limited studies on amphipods. Di-ethylhexyl phthalate (DEHP) and dibutyl phthalate (DBP) are banned in some countries and categorised as substances of very high concern. This study aimed to investigate the effects of NBBS, TPHP, DEHP and DBP on the swimming activity of a coastal intertidal marine amphipod, Echinogammarus marinus. Furthermore, this study is the first to quantify startle response in E. marinus in response to light stimuli. Amphipods were exposed to 0, 0.5, 5, 50 and 500 μg/l concentrations of all test compounds. Swimming activity and startle responses were assessed by video tracking and analysis using an 8-min alternating dark and light protocol after exposure on days 7 and 14. We observed an overall compound and light effect on the swimming activity of E. marinus. A significant decrease in swimming distance was found in 500 μg/l NBBS and TPHP. We observed that the startle response in E. marinus had a latency period of >2 s and animals were assessed at 1 s and the sum of the first 5 s. There was a clear startle response in E. marinus during dark to light transition, evident with increased swimming distance. NBBS exposure significantly increased startle response at environmental concentrations, while significant effects were only seen in 500 μg/l TPHP at 5 s. We found no significant effects of DEHP and DBP on swimming behaviour at the concentrations assessed. The findings of this study affirm the necessity for a continuous review of plastic additives to combat adverse behavioural effects that may be transferable to the population levels.

WITHDRAWN: Handling procedures in ornamental fishing affect the behavioural response of dwarf cichlids (Apistogramma juruensis)

Ornamental fish species are often subjected to netting stress and subsequent air exposure during harvesting and often returned to the water as non-targeted fish species with an assumption that the entire process poses no threat to the behaviour and welfare of these fish species. However, despite the increasing number of scientific research on the welfare of fish species, the ornamental species have been understudied. Here we examined the behavioural response of Apistogramma juruensis (n=40, 0.556±0.23g) to acute handling stress under laboratory conditions. The fish species were exposed to a control group (T1), 10 secs netting (T2), 10 secs netting plus 30 secs air exposure (T3), 10 secs netting plus 60 secs air exposure (T4) to simulate durations of handling stress as obtainable in the ornamental fish trade sector. Video recordings of the behavioural traits of the fish species were done. A. juruensis were randomly assessed for behavioural (swimming (active swimming (AS) and inactive swimming (IS), feeding (latency to feed (LF) and feed intake (FI), aggression (AG), opercula beat rate (OBR) and shelter use (SU) traits. Statistical analyses were performed using linear mixed-effect models in the R Statistical tool (v 4.2.1). The interaction between treatment and weight influenced (p<0.05) the swimming pattern of the fish. AS was significantly (p<0.01) different between treatments and IS was similar (p=0.427) in T1 and T2. LF was highest in T4 and weight (LME, Weight: df = 34.00, t= -1.731, p=0.09, mR2 = 0.929, cR2 = 0.944) did not affect the LF of A. juruensis. In addition, the weight (LME, Weight, p=0.831) of the A. juruensis did not affect the FI. A. juruensis was most aggressive in T2 with significant (LME: Treatment; t = 2.49, df = 133.09, p <0.01, mR2 = 0.415, cR2 = 0.529) differences between treatments. Handling stressors affected (p<0.01) the OBR and this increased with treatment. Fish in T4 spent 66.9% of their time close to the shelter compared to T1 and the effect of weight indicated that larger-sized fish had a higher duration of SU (LME: Weight: t =10.53, df =59.38 p = 0.05, mR2 =0.86, CR2 = 0.95). However, the treatments applied did not result in mortality during the study. In conclusion, our study provides insight into the behavioural implication of netting stress and air exposure during ornamental fish handling and highlights how this could alter the welfare of A. juruensis.

Effects of 4 Testing Arena Sizes and 11 Types of Embryo Media on Sensorimotor Behaviors in Wild-Type and chd7 Mutant Zebrafish Larvae.

The larval zebrafish is a highly versatile model across research disciplines, and the expanding use of behavioral analysis has contributed to many advances in neuropsychiatric, developmental, and toxicological studies, often through large-scale chemical and genetic screens. In the absence of standardized approaches to larval zebrafish behavior analysis, however, it is critical to understand the impact on behavior of experimental variables such as the size of testing arenas and the choice of embryo medium. Using a custom-built, modular high-throughput testing system, we examined the effects of 4 testing arena sizes and 11 types of embryo media on conserved sensorimotor behaviors in zebrafish larvae. Our data show that testing arena size impacts acoustic startle sensitivity and kinematics, as well as spontaneous locomotion and thigmotaxis, with fish tested in larger arenas displaying reduced startle sensitivity and increased locomotion. We also find that embryo media can dramatically affect startle sensitivity, kinematics, habituation, and prepulse inhibition, as well as spontaneous swimming, turning, and overall activity. Common medium components such as methylene blue and high calcium concentration consistently reduced startle sensitivity and locomotion. To further address how the choice of embryo medium can impact phenotype expression in zebrafish models of disease, we reared chd7 mutant larvae, a model of CHARGE syndrome with previously characterized morphological and behavioral phenotypes, in five different types of media and observed impacts on all phenotypes. By defining the effects of these key extrinsic factors on larval zebrafish behavior, these data can help researchers select the most appropriate conditions for their specific research questions, particularly for genetic and chemical screens.

Discrepancies in recommendations for return to regular activities after cervical spine surgery: A survey study

BackgroundThe recommended timing for returning to common activities after cervical spine surgery varies widely among physicians based on training background and personal opinion, without clear guidelines or consensus. The purpose of this study was to analyze spine surgeons’ responses about the recommended timing for returning to common activities after different cervical spine procedures. MethodsThis was a survey study including 91 spine surgeons. The participants were asked to complete an anonymous online survey. Questions regarding their recommended time for returning to regular activities (showering, driving, biking, running, swimming, sedentary work, and nonsedentary work) after anterior cervical decompression and fusion (ACDF), cervical disc replacement (CDR), posterior cervical decompression and fusion (PCDF), and laminoplasty were included. Comparisons of recommended times for return to activities after each surgical procedure were made based on surgeons’ years in practice. ResultsFor ACDF and PCDF, there were no statistically significant differences in recommended times for return to any activity when stratified by years in practice. When considering CDR, return to non-sedentary work differed between surgeons in practice for 10 to 15 years, who recommended return at 3 months, and all other groups of surgeons, who recommended 6 weeks. Laminoplasty surgery yielded the most variability in activity recommendations, with earlier recommended return (6 weeks) to biking, non-sedentary work, and sedentary work in the most experienced surgeon group (>15 years in practice) than in all other surgeon experience groups (3 months). ConclusionsWe observed significant variability in surgeon recommendations for return to regular activities after cervical spine surgery.

A deep learning-based biomonitoring system for detecting water pollution using Caenorhabditis elegans swimming behaviors

Caenorhabditis elegans is a representative organism whose DNA structure has been fully elucidated. It has been used as a model organism for various analyses, including genetic functional analysis, individual behavioral analysis, and group behavioral analysis. Recently, it has also been studied as an important bioindicator of water pollution. In previous studies, traditional machine learning methods, such as the Hidden Markov Model (HMM), were used to determine water pollution and identify pollutants based on the differences in the swimming behavior of C. elegans before and after exposure to chemicals. However, these traditional machine learning models have low accuracy and a relatively high false-negative rate. This study proposes a method for detecting water pollution and identifying the types of pollutants using the Long Short-Term Memory (LSTM) model, a deep learning model suitable for time-series data analysis. The swimming activities of C. elegans in each of the image frames are characterized by the Branch Length Similarity (BLS) entropy profile. These BLS entropy profiles are converted into input vectors through additional preprocessing using two clustering methods. We conduct experiments using formaldehyde and benzene at 0.1 mg/L each, with observation time intervals varying from 30 to 180 s. The performance of the proposed method is compared with that of the previously proposed HMM approach and variants of LSTM models, such as Gated Recurrent Unit (GRU) and Bidirectional LSTM (BiLSTM).

Survival and swimming performance in small-sized South European Cypriniformes tagged with passive integrated transponders

A fundamental assumption in animal telemetry is that the behavior and performance of tagged animals do not substantially deviate from that of untagged animals. For fish, swimming behavior is fundamental for every part of a fish post-hatch life, influencing predator-prey interactions, movement ecology, and habitat choice. Here, we study the effects of PIT-tagging on survival and a range of swimming behaviors for South European nase (Protochondrostoma genei) and brook barbel (Barbus caninus), two small-sized, stream-dwelling cypriniforms native to the Italian peninsula. Effects on volitional swimming activity (sustained swimming) and maximum swimming speed (escape response; burst swimming) were tested in arena trials. Tagging effects on the prolonged swimming performance were tested in South European nase in an increasing velocity time-to-fatigue test, while a barrier passage test was designed to further investigate tagging effects in brook barbel. Both species displayed very high survival (95–100%), with no difference between tagged and control fish. No fish lost a tag during the 64 days of the study, and no tagging effect on swimming activity, prolonged swimming performance, barrier passage rate, or escape response was detected. Our results indicate that PIT-telemetry is a suitable tool to study the tested fish species.

2,4-D-based herbicide underdoses cause mortality, malformations, and nuclear abnormalities in Physalaemus cuvieri tadpoles

Amphibians are considered bioindicators of the environment due to their high sensitivity and involvement in terrestrial and aquatic ecosystems. In the last two decades, 2,4-D has been one of the most widely used herbicides in Brazil and around the world, as its use has been authorized for genetically modified crops and therefore has been detected in surface and groundwater. Against this background, the aim of this work was to investigate the effects of environmentally relevant concentrations of 2,4-D-based herbicides on survival, malformations, swimming activity, presence of micronuclei and erythrocyte nuclear abnormalities in Physalaemus cuvieri tadpoles. The amphibians were exposed to six concentrations of 2,4-D-based herbicides: 0.0, 4.0, 30.0, 52.5, 75.0, and 100 μg L−1, for 168 h. At concentrations higher than 52.5 μg L−1, significantly increased mortality was observed from 24 h after exposure. At the highest concentration (100 μg L−1), the occurrence of mouth and intestinal malformations was also observed. The occurrence of erythrocyte nuclear abnormalities at concentrations of 30.0, 52.5, 75.0 and 100 μg L−1 and the presence of micronuclei at concentrations of 52.5, 75.0, and 100 μg L−1 were also recorded. These effects of 2,4-D in P. cuvieri indicate that the ecological risk observed at concentrations above 10.35 μg L−1 2,4-D may represent a threat to the health and survival of this species, i.e., exposure to 2,4-D at concentrations already detected in surface waters in the species' range is toxic to P. cuvieri.

Continuous sound from a marine vibrator causes behavioural responses of free-ranging, spawning Atlantic cod (Gadus morhua)

Marine vibrators are a new technology being developed for seismic surveys. These devices can transmit continuous instead of impulsive sound and operate over a narrower frequency band and at lower peak pressure than airguns, which is assumed to reduce their environmental impacts. We exposed spawning Atlantic cod (Gadus morhua) to sound produced by a prototype, but full-scale, marine vibrator, and monitored behavioural responses of tagged cod using acoustic telemetry. Fish were exposed to 10 × 3 h continuous sound treatments over a 4-day period using a randomised-block design. Sound exposure levels were comparable to airgun exposure experiments conducted previously with the same set-up ranging from ∼115 to 145 dB re 1 μPa2s during exposure. Telemetry data were used to assess 1) whether marine vibrator exposure displaced cod from the spawning ground, through estimation of residence and survival probabilities, and 2) fine-scale behavioural responses within the test site, namely swimming depth, activity levels, displacement, and home ranges. Forty-two spawning cod were tagged prior to the exposure, with 22 present during the exposure. All 22 tags were equipped with pressure sensors and ten of these additionally with accelerometers. While no premature departure from the spawning site was observed, cod reacted to the exposure by decreasing their activity levels (by up to 50%, SE = 7%) and increasing their swimming depth (by up to 2.5 m, SE = 1.0 m) within the test site during the exposure period. These behavioural responses varied by sex and time of day. Cod reactions to a marine vibrator may be more pronounced than reactions to airguns, possibly because continuous sound is more disturbing to fish than intermittent sound at the same exposure levels. However, given sample size limitations of the present study, further studies with continuous sound are necessary to fully understand its impact and biological significance.

Monitoring welfare indicators of rainbow trout (Oncorhynchus mykiss) in a commercial organic farm: Effects of an innovative diet and accelerometer tag implantation

To meet the growing demand for aquatic products, the aquaculture sector is expanding, including organic aquaculture. One of the main challenges in this industry is the development of suitable fish feeds. EU regulations have made recommendations, including the incorporation of fishmeal from organic aquaculture trimmings. However, the use of such fish meal may pose issues due to lower protein content and elevated phosphorus concentrations that could conflict with national environmental regulations. Thus, there is a pressing need for innovative research to formulate environmentally friendly feeds for organic aquaculture. This study aims to evaluate the feasibility of utilizing an innovative organic feed derived from trimmings (substitution of 64.3% of dietary fish meal trimmings with fishmeal protein concentrate from trimmings) for rainbow trout (Oncorhynchus mykiss). This study assessed the impact of this innovative diet on rainbow trout welfare over a two-month period in real-farming conditions, using: (i) growth parameters, (ii) external morphological damages, (iii) swimming activity, used as a proxy for energy expenditure, and (iv) blood and liver health and welfare indicators. Given that fish swimming activity was evaluated using surgically implanted accelerometer tags, we also investigated the potential adverse effects of implanting these tags on fish welfare. Our findings indicate that accelerometer implantation did not significantly affect fish welfare, but a 18.6% reduction in specific growth rate was shown in tagged fish compared to their non-tagged counterparts. Importantly, the innovative diet did not impair health and welfare indicators of blood and liver or lead to external morphological abnormalities. An increased energy expenditure in fish fed the innovative diet compared to those on a control diet was, however, shown, but there was no observable impact on growth performance. The use of this innovative diet may offer a viable solution to reduce the release of soluble phosphorus into the environment while maintaining appropriate standards for fish growth and welfare in organic conditions. Nevertheless, long-term consequences should be explored.